Ecological
Acoustic Recorder (EAR)
The
EAR is a digital, low power acoustic recording system designed
for long-term monitoring of natural and anthropogenic sounds
between 20 Hz and 30 kHz in aquatic habitats (Fig. 1). It
was developed jointly between the Hawaii
Institute of Marine Biology (HIMB), the National Oceanic
and Atmospheric Administration's (NOAA) Coral
Reef Ecosystem Division (CRED) and OSI. There are three
types of EAR: a shallow-water (0 - 36 m) version that is diver-deployed,
a deep-water version that can be deployed to a depth of 500
m and an extra-deep version deployable to 1000 m. The Deep
and Xtra-deep EARs are recovered by activating an acoustic
release that allows the unit to float back to the surface.
EARs can be deployed for one year or longer, depending on
the number of batteries included and the recording schedule.
Deep EAR deployments are limited by the batteries of the acoustic
releases.
The system is based
on a Persistor CF2 microprocessor and a 16-bit analog-to-digital
converter that records the ambient sound field on a duty cycle
and stores the recordings on an onboard 160 Gb disk. Recordings
are initiated in two ways: on a software-regulated schedule
and on an analog start trigger set to a specific received
acoustic energy threshold (used for detecting transient sounds
such
as vessel engine noise). For a detailed description of the
EAR download this PDF
To date, the EAR
has been used to record long-term acoustic patterns on coral
reefs, to monitor vessel traffic in marine reserves, to track
the occurrence of cetaceans, and to establish the acoustic
signaling behavior of a variety of fish.
Working
with the EAR
There are three
ways to work with the EAR: as an Instrument Leaser (IL), as
a Data Solicitor (DS), or as a Project Collaborator (PC).
The cost will depend on the type of contract agreement established.
The three categories are summarized as follows:
Instrument
Leaser –
For individuals or agencies that want to work with the EAR,
but that do not require any data analysis support. EAR units
are leased form OSI on a 6-month basis and are returned upon
completion of the contract.
Data
Solicitor
– For individuals or agencies interested in an acoustic
monitoring product with no desire to interface directly with
the raw acoustic data. EAR units are deployed at specified
sites for the desired duration and OSI is contracted to analyze
the data and produce a report summarizing the results.
Project
Collaborator
– A special agreement can be set up when the user’s
research objectives are closely matched with OSI’s interests.
The user's costs are significantly less for long-term use
of EARs and the results are shared with OSI. Presentations/publications
are authored jointly. EAR units are returned to OSI at the
end of the collaboration period.
For cost information
please contact Dr. Marc Lammers (lammers@oceanwidescience.org)
